Stroke and TIA - Acute investigation and Management Flashcards
Investigations of stroke
Blood tests
- Us and Es
Risk factors for atheroma
- BP
- Blood tests
- Glucose
- Cholesterol
- Thyroid function (AF risk)
- LFT (alcohol consumption)
Sources Embolism
- Heart
- ECG
- Echo (cardiac thrombus, valvular disease)
- Blood cultures
- 24hr tape
- Neck and intracranial vessels
- Carotid doppler
- Angiogram/MRI
Causes of tendancy to thrombosis
- Blood tests
- FBC
- Thrombophillia screen (protein C+S, lupus anticoag)
- Sickle cell screen
Causes of inflammatory vascular disease
- Blood tests
- ESR
- Syphillis serology
- Temporal art biopsy
Bold = all stroke patients
Imaging
- CT to differentiate between infarct and haemorrhage
Difference beetween infarct and haemorrhage on CT?
Dark = infarction
White = haemorrhage
Key questions to ask yourself when assessing a stroke
1. Is it a stroke
2. What kind of stroke
CT/MRI
History and exam
3. Why did the stroke occur
Ix used depends on the clinical picture
Eg:
Possible cardiac source? Full cardiac work up
Small stroke anterior circulation? Carotid doppler
Haemorrhagic? Clotting profile, cerebral angiography (AV malformations)
4. Worsening factors
Systemic metabolic disturbances
Esp hypoxia and hyperglycaemia will affect function of ischaemic brain and worsen stroke
Appropriate fluid balance/monitor Us and Es
If someone presented with clinical features suggestive of a stroke, what would you do?
- ABCDE
- History - Exact onset, changes/progression, Risk factors
- Examination - full neuro exam, systemic and risk fcator exam
- CT - within 1 hour presentation
When would you treat hypertension in someone presenting with a stroke?
- Hypertensive emergency (encephalopathy/aortic dissection)
- If thrombolysis is being considered
How long after presentation with symptos of a stroke should someone get a CT head?
Within 1 hour
When is CT/MRI within the first hour of presentation with stroke sypmtoms essential?
- If thrombolysis considered
- High risk of haemorrhage
- Unusual presentation - fluctuating consciousness
What is the most sensitive imaging modality for detecting acute infarction?
Diffusion-weighted MRI
What happens at a cellular level when cerebral infarction occurs?
Hypoxic damage:
-
Na+/K+ pump Fails -> Na+ accumulates in the cell -> osmotic shift into cell -> cellular swelling
- Cells in the immediate area around the infarct die very quickly, as they swell and burst. Cells in āpenumbraā are relatively less oematous, and can be āsavedā
-
Excitotoxicity - Damage as a result of prolonged depolarisation of cells in affected area
- Results in failure of AMPA and NMDA receptors - allows excessive calcium into the cell. This causes release of free radicals, production of cytokines, and direct apoptotic effects in the penumbra
What specific things might you look for on examination in someone presenting with features of a stroke?
- Thorough, full neruo exam - clinical diagnosis and lesion localisation
- Pulse (AF)
- Heart sounds (valve disorders)
- Carotid Bruit
- Signs of PVD
- Bruising/Bleeding
- Xanthalasma/Xanthoma/Corneal arcus
- Tar Staining
When would you consider thromblysis in someone presented with a stroke?
Once haemorrhage has been excluded as cause, and within 4.5 hour window of onset (benefits outweigh risks within this window)
Within what time frame are the best results achieved using thrombolysis?
Within 90 minutes of onset
What thrombolytic agent is most commonly used in stroke management?
Alteplase
What are contraindications to thrombolysis in a stroke?
Look them up - Impossible to remember all of them!!! - think of categories of contraindications
- Stroke related
- Neurological
- Bleeding tendency
- Trauma
- Medical problems
What are stroke related contraindications to thrombolysis
- Rapidy improving symptoms
- Ischaemia of >1/3 MCA territory
- Symptoms suggestive of SAH
- Seizure at start of stroke
What are neurological contraindications to thrombolysis?
History of intracrnal bleed, aneurysm or neoplasma
Spinal or cranial surgery/injury
What bleeding tendency risk factors are contraindicaitons to thrombolysis?
- Significant bleeding disorder
- Therapeutic anticoagulation - LMWH, DOACs, Warfarin
- Iron deficiency anaemia
- Thrombocytopenia
- Advanced liver disease
What are trauma related contraindications to thrombolysis in stroke?
- Significant head injury <3 months
- Major surgery/delivery/external heart massage <2 weeks
- Puncture of non-compressible blood vessel <2 weeks
What medical problems are contraindications for thrombolysis in stroke?
- SBP > 180/DBP >110
- Active internal bleeding
- Aortic aneurysm
- Bacterial endocarditis/pericarditis
- Acute pancreatitis
- Haemorrhagic retinopathy
- Oesophageal varices
- Ulceratie GI disease <3 months
- GI/GU haemorrhage < 3 weeks
If thrombolysis was contraindicated, what treatment would you start someone on for acute treatment of a stroke?
Aspirin PO/PR OD for 2 weeks
Why does diffusion weighted MRI detect early abnormalities seen in infarction better than normal MRI or CT?
This type of MRI exploits the fact that damaged cells fill with water ā and thus contain more water than normal cells in the early stages of damage.
What intial investigations would you consider doing in someone presenting with a stroke?
- CT/MRI - within 1 hour
- MRI angiography
- ECG
- CXR
- Bloods - ESR, FBC, clotting screen, glucose, Lipids/cholesterol
Why might you do an ESR on someone presenting with features of a stroke?
If with headache and tender scalp - Giant cell arteritis
Why might you do FBC or clotting in someone presenting with a stroke?
Look for evidence of clotting/bleeding disorders - thrombocytopenia, polycythaemia
What would you want to prioritise in your ABCDE assessment in someone presenting with a stroke?
- Maintain airway
- Prevent hypoxia
- Hydrate
- Treat fever / source of fever ā this can help to limit the extent of damage
- Treat hypo / hyperglycaemia
What dose of aspirin would you give someone if thrombolysis was contraindicated?
300 mg
How long would you put someone on aspirin treatment for following a stroke?
2 weeks
Primary management of ischemic stroke?
Thombolysis within 4 hours - alteplase, consider contraindications.
Aspirin (300mg) daily - given as soon as possible after onset of stroke symptoms once brain imaging has excluded haemorrhage
Hypertension managment - only lowered in acute stage where there are liekly to be complications (hyptensive encephalopathy, HF or aortic dissection)
Secondary stroke management of ischaemic stroke
- Anti-hypertensives (ACEI)
- Antiplatelets (Aspirin + Dipyridamole or Clopidogrel)
- Statins
- Warfarin for AF
What medication would you start someone on following 2 weeks of aspirin treatment?
- Clopidogrel long term - monotherapy
- Consider Warfarin if AF the cause
- Statin - 48 hours after stroke
What dose of clopidogrel would you give someone as long-term prophylaxis?
75 mg OD
What could you give someone if they did not tolerate clopidogrel for post-stroke prophylaxis?
Slow-release dipyridamole
What is the definition of a transient ischaemic attack?
A brief episode of neurological dysfunction due to temporary focal cerebral or retinal ischaemia without infarction, e.g. a weak limb, aphasia or loss of vision, usually lasting seconds or minutes with complete recovery. TIAs may herald a stroke. The arbitrary time of <24 hours is no longer used.
If someone presented with a TIA with amaurosis fugax, where might the occlusion be taking place?
Retinal artery occlusion
What are causes of TIA?
- Atherothromboembolism
- Cardioembolism - Mural thrombus, AF, Valve disease
- Hyperviscosity - polycythaemia, sickle-cell, myeloma
- Vasculitis - cranial arteritis, SLE, PAN
What are features of an anterior circulation TIA?
Carotid system
- Amaurosis fugax
- Aphasia
- Hemiparesis
- Hemisensory loss
- Hemianopic visual loss
What are features of a posterior circulation TIA?
- Diplopia, vertigo, vomiting
- Choking and dysarthria
- Ataxia
- Hemisensory loss
- Hemianopic visual loss
- Bilateral visual loss
- Tetraparesis
- Loss of consciousness (rare)
- Transient global amnesia (possibly)
If, on examination of someone presenting with signs of a TIA, you found there to be central retinal artery occlusion, where might this suggest there is stenosis in the carotid system?
Internal carotid artery stenosis
What differentials would you want to consider in someone presenting with features of a TIA?
- Hypoglycaemia
- Migraine aura
- Focal epilepsy
- Hyperventilation
- REtinal bleeds
- Malignant hypertension
- MS
- Intracrnaial tumours
- Peripheral neuropathy
- Phaeochromocytoma
- Somatization
What investigations would you consider doing in someone with a suspected TIA?
- Bloods - FBC, U+Eās, Glucose, Lipids
- CXR
- ECG
- Carotid doppler +/- angio
- CT/Diffusion weight MRI
- ECHO
How would you manage someone with a TIA?
- Control risk factors - BP, DM, Hyperlipidaemia, Smoking
- Antiplatelet therapy - Aspirin (300mg) for 2 weeks, then clopidogrel (75mg) long-term
- Consider anticoagulation - AF
- Consider carotid endartectomy - within 2 weeks of presentation if >70% stenosis and no contrindiations
How long after a TIA are individuals not allowed to drive?
1 month - Need to inform DVLA if stll symptomatic after 4 weeks or HGV driver
What scoring system could you use to stratify those who have had a TIA who might be at higher risk of stroke in the future?
ABCD2 score - score >/=4 indicates high risk of early stroke - assess by specialist in 24 hours
Contraindications to thrombolysis
AGAINST
Aortic dissection
GI Bleeding - internal bleeding
Allergic reaction previously
Iatrogenic - recent surgery
Neurological - cerebral enoplasm, recent haemorrhage stroke (on CT), low GCS
Severe hypertension (>180/90mmHg)
Trauma - including CRP
So - NO MOTOR DEFICIT, SYMPTOM ONSET >3HOURS< IMPARIED CONSCIOUSNESS, COAGULOPATHY (INR>1.8)
How does alteplase work
Converts plasminogen to plasmin which degrades fibrin to FDP
Ie decreaese platelet aggregation
Potential surgical management of stroke
Carotid endarterectomy - for those with >70% stenosis (surgical excision of atheromatous segments)
Large intracranial haematoma (surgical excision)
Large cerebellar stroke (brain stem compression)
Secondary stroke managmenet:
ASPIRIN: SE, Cautions, Contraindications
CLOPIDOGREL: When, SE
Aspirin:
- 300mg 2 weeks
- NSAIDs can antagonise effects so withhold during 2 weeks of aspiring use
- Inhibits thromboxane 2
- SE: GI irritation/bleed
- Cautions - asthma, uncontrolled hypertension, previous peptic ulcer
- Contraindications - Known allergies, GI ulcers, pregnant
Clopidogrel
- 2 weeks postischaemic (after aspirin) or post TIA
- SE: Dyspepsia, abdo pain
- PPIs could reduce efficacy
Secondary stroke management:
STATINS
SE, Monitoring, Interactions, whats first line
SE: Myopathy, GI effect, altered LFTs
Monitoring: LFTs measured prior to therapy after 12 weeks and then annually, non fasting total cholesterol, TFTs, HbA1C
Interactions: Antiarrhythmitics, antibiotics (macrolides) - stop statin for period for period of antibiotic use, anticoagulants, graperuit juice
First line: Atorvostatin 80mg
Secondary stroke management:
Antihypertensives
Common used?
SE
Monitoring
Perindopril and indapamide
SE: Dry cough, dizziness/first dose hyptension, AKI, angioedma, hyperkalaemia
Monitoring: Us and Es (renal function, potassium)
Secondary strok managmenet:
Anticoagulants
When used?
When witheld?
When used - ischaemic patients with AF
Aspirin 3 days then start anticoagulant
Eg Endoxaban
What medication would you expect someone to be on day 2 post stroke?
Aspirin
Artorvostatin
What medication would you expect someone to be on 16 days post stroke?
Clopidogrel
Atorvostatin
Perindopril
Indapamide
Endoxaban in patinets with AF
Carotid symptoms TIA
(POSTERIOR)
Amarosis fugax
Aphasia
Hemiparesis
Hemisensory loss
Hemianopia visual loss
Vertebro-basillar teritory symptoms
(ANTERIOR)
Diplopia
Vertigo
Vomiting
Dysarthria
Choking
Ataxia
Hemisensory loss
Visual loss
Paresis
Signs of TIA
Carotid bruit
Hypertension
AF
Heart murmur from vascular disease
Fundoscopy during TIA - retinal artery emboli
DDx TIA
Migraine
Partial seizure
Transient global amnesia
Intracranial lesions
Metabolic hypoglycaemia
Peripheral nerve lesions - in intermittent sensory loss
Management of TIA
Aspirin 300mg + Dipyridamole (Clopidogrel if intolerant) - aspirin given 2 weeks after for life post TIA
Warfarin (AF)
Carotid endartectomy
Secondary prevention - control of risk factors
